BUS 254 Study Guide - Final Guide: Interrupt Handler, Arithmetic Logic Unit, Computer Hardware

• School: Simon Fraser University
• Department: Business Administration
• Course: BUS 254
• Professor: Neil Braganza

Document Summary

Presents a virtual machine, abstracted from the hardware. Os provides a variety of services that programs can obtain using system calls. Now: make computer easy to use, by abstraction (processes, files), libraries, . Multiprogramming: having different programs in memory and running them. Timesharing: ability of the computer to be used by multiple ppl simultaneously. Steps: fetch instruction, fetch data, execute, store results, goto 1. Components: control unit, arithmetic logic unit, registers (instruction, pc, stack ptr, psw) Interrupts: happen on a clock interrupt or an i/o interrupt. When a process requires i/o, cpu sets up an interrupt handler, and blocks the process. The interrupt handler copies the information for the current program and runs the next program. When i/o for the last program is done, the interrupt handler runs the interrupt for the new program. Types: registers, cache, main memory, disk all managed by memory management. Protection problem: access to memory for diff programs needs to be under control.